Inside the "End of the Road" bar Bad Larry suggests Stan to kill a guy named Mark, whom happens to be the creator of the TV show "Quintuplets". This may be a reference to Mark Reisman the actual creator of that show; besides, the character resembles a lot to Reisman.
The episode title & the opening sequence where Stan is playing cards is a nod to "The 40 year old Virgin" movie starring Steve Carell where his character is a 40-year-old Virgin & his friends finds out during a game of poker.
Randy is modeled in appearance after Jackie Earle Haley's character in Little Children (2006) who was also a pedophile living with his mother.
One of several episodes that were heavily censored in Germany.
Roger's scene with the rodent on a stick is either completely edited or
makes no sense at all.